JSON Validator
Paste any JSON and instantly check if it is valid. Get precise error messages with location details when something is wrong.
About JSON Validator
The JSON Validator checks whether your JSON text is syntactically correct. If the JSON is valid, it reports key statistics about the structure. If it is invalid, it shows the exact error message from the parser including the position where the error was detected.
Common JSON Errors
- Trailing comma — JSON does not allow a comma after the last item in an array or object.
- Single quotes — JSON requires double quotes for strings and keys.
- Unquoted keys — Object keys must always be quoted strings in JSON.
- Comments — JSON does not support comments (unlike JavaScript or JSON5).
- Missing brackets — Every opening
[or{must have a matching closing bracket.
FAQ
JavaScript objects are more permissive — they allow single quotes, unquoted keys, trailing commas, and comments. JSON is a strict subset that only allows double-quoted strings, no trailing commas, and no comments. This tool validates strict JSON.
Common culprits are invisible characters (like a BOM at the start of the file), curly quotes (" " instead of " "), or a trailing comma after the last key-value pair. Try pasting the error location into a hex viewer if you can't spot it.
Yes. Validation happens entirely in your browser using JavaScript's native JSON.parse(). Your data is never transmitted to any server.